Enteral nutrition is achieved through naso-esophageal intubation of a feeding tube. Typically, the enteral feeding tube is joined to a distensible container, such as a flexible bag similar to that disclosed in U.S. Pat. No. 4,529,102. Several disadvantages may be encountered through the use of enteral feeding bags, chief of which is that the fluid administration system is an open, rather than closed system. That is, because pre-filled enteral feeding bags are difficult to ship, deliver and store, the user is required to fill the bag with enteral nutritional solution before initiating enteral therapy. The handling of the enteral solutions by users often led to potentially septic fluid administration conditions. Hence, in order to develop a closed administration system, it has become important to consider administering enteral nutritional solutions from a sealed, pre-filled, shape retentive container.
One such container which has been successfully utilized in enteral feeding therapy is a shape retentive paperboard carton disclosed in U.S. Pat. No. 4,287,247 and sold under the trademarks TETRA PAK, TETRA BRIK, and BRIK PAK. Such cartons are pre-filled with enteral nutritional fluid and then sealed. However, in using such paperboard cartons in the administration of enteral solutions, it is necessary to utilize a device which can aseptically access the fluid contents of the carton and deliver such fluids at a controlled rate.
One such device is disclosed in U.S. Pat. No. 4,699,296. However, this fluid dispensing device for paperboard cartons has inherent disadvantages. One such disadvantage is that this device requires a rigid cradle structure to support and suspend the carton in a particular angular orientation in which the carton has a single uppermost corner and a single lowermost corner. This cradle is expensive to manufacture and complicates set up of an enteral feeding administration system.
In addition, the dispensing device disclosed in U.S. Pat. No. 4,669,296 includes a fluid dispensing column which is secured to the carton merely by the insertion of dispensing spikes, carried on the column, into apertures on the cradle. Securement of the fluid dispensing column is achieved only by the frictional engagement of the spikes into the puncture holes of the carton. As a result, it is possible for the fluid dispensing column to become disengaged during enteral administration causing leakage or spillage and an inaccurate administration of enteral nutritional solutions.
In addition, the prior art fluid dispensing column disclosed in U.S. Pat. No. 4,699,296 utilizes two dispensing spikes, each positioned near the upper and lower ends of the column. Such prior art spikes have a configuration and structure as disclosed in FIG. 11. The prior art spike is conical from the base of the spike to the point of the spike. In addition, the prior art spike includes a single inlet port located about mid-way along the side wall of the spike. The aperture is in fluid communication with an inner bore having the same diameter as the inlet port and angularly extending into a lumen of the fluid dispensing column as shown in FIG. 11. Because of the use of a single inlet port and a bore, both having limited inner diameters, the prior art dispensing spike restricted fluid flow, thereby resulting in fluid flow rate problems.
Despite restricted fluid flow properties, no fluid leakage problems are encountered upon full penetration and insertion of the spike of FIG. 11 into a shape retentive container. This is believed to be a result of the use of a conical spike tip having an axially centered point which permits a centered penetration of the shape retentive container. As a result of such centered penetration, the container material is turned inwardly to form a uniform margin which circumferentially surrounds the spike. This uniform margin or collar creates a fluid seal which prevents fluid leakage upon full insertion and penetration of the spike into the container. However, because the prior art spike disclosed in FIG. 11 is conical from the point of the spike to the base, leakage results if the spike is slightly withdrawn from the aperture formed in the container. Due to the inclined walls of the base of the spike, a breach of the fluid seal between the margin and the spike itself occurs virtually immediately upon any withdrawal of the spike resulting in substantial fluid leakage.
Hence, prior to the present invention, a need existed for a device for aseptic access and dispensing of enteral feeding fluids from a shape retentive, pre-filled container, such as a BRIK PAK carton, in which proper hanging of the carton can be achieved without the use of rigid cradle structures and permitting a secure attachment of a fluid dispensing column to the container.
A need also existed for a fluid dispensing column for use in penetrating shape retentive containers which utilizes dispensing spikes that maximize fluid flow, utilize centered penetration to eliminate fluid leakage upon full penetration and insertion of the spike into the container and employs an outer spike configuration to avoid fluid leakage from slight, inadvertent withdrawal of the spike from the aperture in the container.